Guidewire for crossing occlusions or stenoses

ABSTRACT

Systems and methods for crossing stenosis, partial occlusions, or complete occlusions within a body lumen. The systems generally include an elongate member such as a hollow guidewire that houses a rotatable and translatable drive shaft. The drive shaft typically has a distal portion that is advanced to create a path in the occlusive material that is large enough to allow the hollow guidewire to cross the occlusive material.

CROSS-REFERENCES TO RELATED APPLICATIONS

The present application is a continuation application of U.S. patentapplication Ser. No. 12/606,931, filed Oct. 27, 2009, which is acontinuation application of U.S. patent application Ser. No. 10/950,161filed Sep. 24, 2004, now U.S. Pat. No. 7,628,763, which is acontinuation application of U.S. patent application Ser. No. 09/644,201,filed Aug. 22, 2000, now U.S. Pat. No. 6,824,550, which claims priorityto U.S. Patent Application No. 60/195,154, filed Apr. 6, 2000, under 37C.F.R. §1.78, the complete disclosures of which are incorporated hereinby reference. The present application is also related to U.S. patentapplication Ser. No. 09/030,657, filed Feb. 25, 1998, now U.S. Pat. No.6,059,767, the complete disclosure of which is herein incorporated byreference.

BACKGROUND

The present invention is generally related to medical devices, kits, andmethods. More specifically, the present invention provides a system forcrossing stenosis, partial occlusions, or total occlusions in apatient's body.

Cardiovascular disease frequently arises from the accumulation ofatheromatous material on the inner walls of vascular lumens,particularly arterial lumens of the coronary and other vasculature,resulting in a condition known as atherosclerosis. Atheromatous andother vascular deposits restrict blood flow and can cause ischemiawhich, in acute cases, can result in myocardial infarction or a heartattack. Atheromatous deposits can have widely varying properties, withsome deposits being relatively soft and others being fibrous and/orcalcified. In the latter case, the deposits are frequently referred toas plaque. Atherosclerosis occurs naturally as a result of aging, butmay also be aggravated by factors such as diet, hypertension, heredity,vascular injury, and the like.

Atherosclerosis can be treated in a variety of ways, including drugs,bypass surgery, and a variety of catheter-based approaches which rely onintravascular widening or removal of the atheromatous or other materialoccluding the blood vessel. Particular catheter-based interventionsinclude angioplasty, atherectomy, laser ablation, stenting, and thelike. For the most part, the catheters used for these interventions mustbe introduced over a guidewire, and the guidewire must be placed acrossthe lesion prior to catheter placement. Initial guidewire placement,however, can be difficult or impossible in tortuous regions of thevasculature. Moreover, it can be equally difficult if the lesion istotal or near total, i.e. the lesion occludes the blood vessel lumen tosuch an extent that the guidewire cannot be advanced across.

To overcome this difficulty, forward-cutting atherectomy catheters havebeen proposed. Such catheters usually can have a forwardly disposedblade (U.S. Pat. No. 4,926,858) or rotating burr (U.S. Pat. No.4,445,509). While effective in some cases, these catheter systems, evenwith a separate guidewire, have great difficulty in traversing throughthe small and tortuous body lumens of the patients and reaching thetarget site.

For these reasons, it is desired to provide devices, kits, and methodswhich can access small, tortuous regions of the vasculature and whichcan remove atheromatous, thrombotic, and other occluding materials fromwithin blood vessels. In particular, it is desired to provideatherectomy systems which can pass through partial occlusions, totalocclusions, stenosis, and be able to macerate blood clots or thromboticmaterial. It is further desirable that the atherectomy system have theability to infuse and aspirate fluids before, during, or after crossingthe lesion. At least some of these objectives will be met by the devicesand methods of the present invention described hereinafter and in theclaims.

SUMMARY

The present invention provides systems and methods for removingocclusive material and passing through occlusions, stenosis, thrombus,and other material in a body lumen. More particularly, the presentinvention can be used passing through stenosis or occlusions in a neuro,cardio, and peripheral body lumens. Generally, the present inventionincludes an elongate member that is positioned adjacent the occlusion orstenosis. A drive shaft having a distal tip is rotated and advanced fromwithin the elongate member to create a path forward of the elongatemember to form a path in the occlusion or stenosis. To facilitatepassing through the occlusion or stenosis, the distal end of theelongate member can be steerable to provide better control the creationof the path through the occlusion or stenosis. Optionally, the targetsite can be infused and/or aspirated before, during, and after creationof the path through the occlusion.

In an exemplary embodiment, the elongate member is a hollow guidewirethat has a flexibility, pushability and torqueability to be advancedthrough the tortuous blood vessel without the use of a separateguidewire. Additionally, the hollow guidewire may be sized to fit withina conventional support or access catheter system and inserted into theblood vessel and delivered to the target site. The catheter system canbe delivered either concurrently with the advancement of the hollowguidewire or after the guidewire has reached the target site. Theposition of the hollow guidewire and catheter system can be maintainedand stabilized while the drive shaft is rotated and translated out ofthe axial lumen of the hollow guidewire. The distal tip of the driveshaft can be deflected, coiled, blunted, flattened, enlarged, twisted,basket shaped, or the like. In some embodiments, to increase the rate ofremoval of the occlusive material, the distal tip is sharpened orimpregnated with an abrasive material such as diamond chips, diamondpowder, glass, or the like.

The drive shaft can be a counter-wound guidewire construction or be of acomposite structure consisting of a fine wire around which a coil iswrapped. The counter-wound or composite constructions are more flexiblethan a single wire drive shaft and can provide a tighter bending radiuswhile still retaining the torque transmitting ability so that it canstill operate as a lesion penetration mechanism.

In a specific configuration, the drive shaft has spiral threads orexternal riflings extending along the shaft. The spirals typicallyextend from the proximal end of the shaft to a point proximal of thedistal tip. As the drive shaft is rotated and axially advanced into theocclusive material, the distal tip creates a path and removes thematerial from the body. The rotating spirals act similar to an“Archimedes Screw” and transport the removed material proximally up thelumen of the elongate member and prevent the loose atheromatous materialfrom escaping into the blood stream.

Systems and kits of the present invention can include a support systemor access system, such as a catheter or guidewire having a body adaptedfor intraluminal introduction to the target blood vessel. The dimensionsand other physical characteristics of the access system body will varysignificantly depending on the body lumen which is to be accessed. Inthe exemplary case, the body of the support or access system is veryflexible and is suitable for introduction over a conventional guidewireor the hollow guidewire of the present invention. The support or accesssystem body can either be for “over-the-wire” introduction or for “rapidexchange,” where the guidewire lumen extends only through a distalportion of the access system body. Optionally, the support or accesssystem can have at least one axial channels extending through the lumento facilitate infusion and/or aspiration of material from the targetsite. Support or access system bodies will typically be composed of anorganic polymer, such as polyvinylchloride, polyurethanes, polyesters,polytetrafluoroethylenes (PTFE), silicone rubbers, natural rubbers, orthe like. Suitable bodies may be formed by extrusion, with one or morelumens that extend axially through the body. For example, the support oraccess system can be a support catheter, interventional catheter,balloon dilation catheter, atherectomy catheter, rotational catheter,extractional catheter, laser ablation catheter, guiding catheter,stenting catheter, ultrasound catheter, and the like.

In other embodiments, a hollow guidewire can be used as the support oraccess system. The hollow guidewire can be navigated to and positionedat the target site, with or without the use of a separate guidewire. Thehollow guidewire support system provides the flexibility,maneuverability, torqueability (usually 1:1), and columnar strengthnecessary for accurately advancing through the tortuous vasculature. Thehollow guidewire support system can act as a working channel inside ofwhich other interventional devices can be delivered to the target site.Such devices include, but are not limited to a rotating guidewire,infusion guidewire, clot maceration guidewire, normal guidewire, and thelike. Because the hollow guidewire is not composed of polymer, thehollow guidewire working channel does not soften at body temperatures.

The hollow guidewire working channel typically has a thin wallconstruction which allows the lumen of the working channel to bemaximized when compared with polymeric based catheter designs. Thisallows larger diameter devices to be inserted into it than can beinserted through similar sized catheter-based devices. The larger lumenof the hollow guidewire working channel allows devices such as clotmacerators and other larger devices to be delivered to the targetlesion. Additionally the larger diameter lumen allows infusion or clotdissolving fluid and/or aspiration of the debris created in the clotmaceration process.

In use, the access system can be delivered to the target site over aconventional guidewire. Once the access system has been positioned nearthe target site, the conventional guidewire can be removed and theelongate member can be advanced through the access system to the targetsite. Alternatively, because the elongate member can have theflexibility, pushability, and torqueability to be advanced through thetortuous regions of the vasculature, it is possible to advance theelongate member through the vasculature to the target site without theuse of a separate guidewire. The access system can be advanced over theelongate member to the target site. Once the elongate member has beenpositioned at the target site, the drive shaft is rotated and advancedinto the occlusive material. The rotation of the distal tip creates apath forward of the elongate member. In some embodiments the pathcreated by the distal tip has a path radius which is larger than theradius of the distal end of the elongate member. In other embodiments,the path created by the distal tip has a path radius which is the samesize or smaller than the radius of the elongate member.

One exemplary system for crossing an occlusion or stenosis within a bodylumen comprises a drive shaft that is rotatably and translatablyreceived within an axial lumen of an elongate member. Means at a distalportion of the drive shaft creates a path in front of the elongatemember to facilitate crossing of the occlusion or stenosis. The means ismoveable between an axially retracted configuration and an axiallyextended configuration. The means in the axially extended configurationcreates a profile that is at least as large as the diameter of thedistal end of the elongate member. In alternative implementations, thepath creating means can move from the retracted position to an extendedconfiguration that has a profile with the same or smaller profile thanthe distal end of the elongate member.

In another aspect, the present invention provides a system for crossingan occlusion or stenosis within a body lumen. The system comprises anelongate member having a proximal end, a distal end, and a lumen. Adrive shaft is rotatably and translatably disposed in the elongatemember and is removably attached to a rotating mechanism. The rotatingmechanism rotates the drive shaft so that a distal tip can be advancedbeyond the distal end of the elongate member to create a path throughthe occlusion or stenosis such that the elongate member can be advancedpast the occlusion or stenosis. In a specific implementation, therotating mechanism can be detached from the drive shaft and an accesssystem can be delivered to the target site over the elongate member.Thereafter, the rotating mechanism can be reattached and the drive shaftcan be rotated.

In yet another aspect, the present invention provides an assembly forcrossing an occlusive or stenotic material in a body lumen. The assemblycomprises a guidewire having an axial lumen. A drive shaft rotatably andtranslatably extends through the axial lumen of the guidewire. The driveshaft has a distal tip that can be rotated and advanced to create a paththrough the occlusive or stenotic material. In some embodiments, theguidewire has an outer diameter or periphery similar to conventionalpassive guidewires used for neuro, cardio, and peripheral interventions.The outer diameter or periphery of the guidewire having an axial lumenis typically between approximately 0.040 inches and 0.009 inches, andpreferably between approximately 0.024 inches and 0.009 inches, andtypically between 0.013 and 0.014 inches. Depending on the body lumenthat is accessed, the outer diameter of the guidewire can be larger orsmaller. In most embodiments, the guidewire has the torqueability,pushability, and steerability to be advanced through the body lumen.

In yet another aspect the present invention provides a guidewire systemfor passing through occlusions or stenosis. The system comprises ahollow guidewire having a distal end, a proximal end, and a lumen. Adrive shaft is movably disposed within the hollow guidewire such that adistal tip portion can extend beyond the distal end of the hollowguidewire. A rotating mechanism can rotate the drive shaft and anactuator can be used to control the axial movement of the drive shaft.Activation of the actuator moves the distal end of the rotating driveshaft along its longitudinal axis to create a path through the occlusionor stenosis.

In yet another aspect, the present invention provides a method ofcrossing an occlusion or stenosis within a body lumen. The methodcomprises positioning an elongate member and a drive shaft in the bodylumen. The drive shaft is rotated. The drive shaft is expanded from aretracted configuration to an expanded configuration. In the expandedconfiguration, the drive shaft creates a path that is at least as largeas the perimeter of the distal end of the elongate member. The distalportion of the drive shaft is then advanced into the occlusion orstenosis to create a path in the occlusion or stenosis.

In another aspect the present invention provides a method of crossing anocclusion or stenosis within a body lumen. The method comprisesadvancing a guidewire through the body lumen. An access or supportsystem is moved over the guidewire to the occlusion or stenosis. Theguidewire is removed from the body lumen and a steerable elongate memberhaving a drive shaft is passed through the lumen of the access system.The drive shaft is rotated within a lumen of the elongate member. Thedrive shaft is advanced from a retracted position to an extendedposition to create a path through the occlusion or stenosis.

In yet another aspect, the present invention provides a method ofpassing through an occlusive or stenotic material in a body lumen. Themethod comprises positioning a hollow guidewire with a drive shaftadjacent the occlusion. A drive shaft is rotated and advanced out of thehollow guidewire and into the occlusive or stenotic material to create apath through the occlusive or stenotic material. In some embodiments,the guidewire can then be moved through the occlusive or stenoticmaterial and an access system can be positioned in the path through theocclusive or stenotic material. The remaining occlusive or stenoticmaterial can then removed with the access system.

In another aspect, the present invention provides a kit. The kit has ahollow guidewire having a lumen. A rotatable drive shaft having a shapeddistal tip is removably received within the lumen of the hollowguidewire. Instructions for use in passing occlusions or stenosis in abody lumen comprise rotating the inner wire within the steerable hollowguidewire and advancing the drive shaft into the occlusive or stenoticmaterial to create a path through the occlusive or stenotic material. Apackage is adapted to contain the hollow guidewire, rotatable wire, andthe instructions for use. In some embodiments, the instructions can beprinted directly on the package, while in other embodiments theinstructions can be separate from the package.

These and other aspects of the invention will be further evident fromthe attached drawings and description of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows an elevational view of a system of the present invention;

FIG. 1B shows manual manipulation of the drive shaft;

FIG. 2 shows a distal end of the elongate member and a distal tip of adrive shaft of the present invention;

FIG. 3 is a cross sectional view of the device along A-A of FIG. 2;

FIG. 4 shows a diamond chip embedded distal tip of the drive shaft;

FIG. 5A shows a deflected distal tip in a position forward of the distalend of the elongate member;

FIG. 5B shows the flexible deflected distal tip in a fully retractedposition within the axial lumen of the elongate member;

FIG. 5C shows a deflected distal tip in a retracted position with thedistal tip partially extending out of the elongate member;

FIG. 6A shows a sharpened deflected distal tip extending out of theelongate member;

FIGS. 6B and 6C show the cutting edges on the deflected distal tip ofFIG. 6A;

FIG. 6D shows the distal tip deflected off of the longitudinal axis ofthe drive shaft;

FIGS. 6E and 6F is a partial cut away section of two counter-wound driveshafts of the present invention;

FIG. 6G shows the relative flexibility between a conventional driveshaft and a counter-wound drive shaft of the present invention;

FIGS. 7A to 7C illustrate a method of forming the deflected distal tipusing a fixture;

FIGS. 8A-8K show a variety of tip configurations;

FIG. 8L shows a distal tip having a flattened and twisted configuration;

FIGS. 8M-8P show an exemplary method of manufacturing the distal tip ofFIG. 8L;

FIG. 9 shows a drive shaft having spirals or external riflings whichfacilitate the proximal movement of the removed occlusive or stenoticmaterial;

FIG. 10 shows a linkage assembly between the motor shaft and the driveshaft;

FIGS. 11A and 11B show an alternative linkage assembly coupling themotor shaft and the drive shaft;

FIGS. 12-14 show a luer connection assembly which couples the elongatemember to the housing;

FIG. 15 shows a system having an access system, a hollow guidewire witha deflectable distal end, and a drive shaft;

FIGS. 16A to 16E illustrate a method of the present invention;

FIGS. 17A to 17E illustrate another method of the present invention;

FIGS. 18A to 18B illustrate yet another method of the present invention;and

FIG. 19 shows a kit of the present invention.

DETAILED DESCRIPTION

The systems, devices and methods according to the present invention willgenerally be adapted for the intraluminal treatment of a target sitewithin a body lumen of a patient, usually in a coronary artery orperipheral blood vessel which is occluded or stenosed withatherosclerotic, stenotic, thrombotic, or other occlusive material. Thesystems, devices and methods, however, are also suitable for treatingstenoses of the body lumens and other hyperplastic and neoplasticconditions in other body lumens, such as the ureter, the biliary duct,respiratory passages, the pancreatic duct, the lymphatic duct, and thelike. Neoplastic cell growth will often occur as a result of a tumorsurrounding and intruding into a body lumen. Removal of such materialcan thus be beneficial to maintain patency of the body lumen. While theremaining discussion is directed at passing through atheromatous orthrombotic occlusive material in a coronary artery, it will beappreciated that the systems and methods of the present invention can beused to remove and/or pass through a variety of occlusive, stenotic, orhyperplastic material in a variety of body lumens.

An apparatus 10 embodying features of the present invention isillustrated in FIG. 1A. The apparatus 10 generally includes a housing 12coupled to an elongate member 14 which has a proximal end 16, a distalend 18, and an axial lumen 20. As shown by arrows 23, 25, the driveshaft 22 is movably received within the axial lumen 20 of the elongatemember 14. The distal tip 24 of the drive shaft 22 has a shaped profilesuch that movement of the drive shaft creates a path forward of thedistal end of the elongate member 14 for passing through the occlusiveor stenotic material. In most configurations, wires 29 couple the drivemotor 26 to the control system 27 and power supply 28. In someembodiments, the power supply 28 is covered with a plastic sheath coverso as to maintain a sterile environment (not shown).

The drive motor 26 is attachable to the proximal end of the drive shaft14 to move (i.e., rotate, translate, reciprocate, vibrate, or the like)the drive shaft 22 and shaped distal tip 24. An input device 82 isattached to the housing 12 to control the rotation and/or axial movementof the drive shaft 22. The proximal end 16 of elongate member 14 iscoupled to the housing 12 through a connector assembly 30. The connectorassembly limits the motion of the elongate member 14 while allowing thedrive shaft 22 to rotate and translate within the elongate member 14.Optionally, some embodiments of the connector assembly 30 includes anaspiration or infusion port (not shown) for facilitating fluid exchange(e.g., delivery or removal) at the target site.

As shown in FIG. 1B, in order to macerate clots and to penetrate softlesions, some drive shafts of the present invention can be configured tobe manually rotated. In such embodiments, the proximal end of the driveshaft 22 can be grasped between the fingers and manually turned torotate the distal tip 24. The proximal end can be optionally fit with aknurled knob 21 or other mechanism which allows manual manipulation ofthe proximal end of the drive shaft 22.

An exemplary embodiment of the elongate member 14 is best seen in FIGS.2 and 3. The elongate member 14 is preferably a flexible, hollowguidewire that has the flexibility, pushability, and torqueability toallow a user to advance the hollow guidewire directly through a tortuousblood vessel to the target site. Because of the high columnar strengthof the hollow guidewire 14 there is typically no need for a separateguidewire.

In the exemplary embodiment illustrated in FIG. 2, the hollow guidewirehas an helically wound elongated shaft which defines an axial lumen 20that receives the drive shaft 22 and which can be used for infusion oraspiration. The elongated shaft includes a proximal outer tube 32, anintermediate coil 34, and a distal coil tip 36. In some embodiments theintermediate coil 34 is made of a stainless steel or nitinol coil, whilethe distal tip 36 is composed of a flexible, radiopaque coil, such asplatinum-iridium. As shown, the intermediate coil 34 is threadedlyengaged with the outer tube 32 and distal tip 36, but it will beappreciated that the intermediate coil 34 can be connected to the outertube 32 and distal tip 36 by any conventional means, e.g. solder,adhesive, or the like. The proximal end of the elongate member 14 can becoupled to a vacuum source or a fluid source (not shown) such that thetarget site can be aspirated or infused during the procedure.

Hollow guidewire 14 is typically sized to be inserted through coronary,neuro, or peripheral arteries and can have a variety of diameters. Theouter diameter of the hollow guidewire is typically betweenapproximately 0.009 inches and 0.040 inches and preferably betweenapproximately 0.009 inches and 0.024 inches so as to ensurecompatibility with existing interventional cardiology catheters andstent systems. The length of the hollow guidewire 14 may be varied tocorrespond to the distance between the percutaneous access site and thetarget site. For example, for a target site within the heart that isbeing accessed through the femoral artery, the hollow guidewire willtypically have a length of approximately 175 cm. It should be notedhowever, that other embodiments of the hollow guidewire 14 may havedimensions that are larger or smaller than the above describedembodiments and the present invention is not limited to the aboverecited dimensions.

Referring now to FIG. 3, a cross section of one embodiment of the hollowguidewire 14 is shown. An inner tube 38 and outer tube 40 are positionedaround coils 34, 36 to provide a flexible, structural support whichprevents liquids from moving between the blood vessel and the axiallumen of the elongate member 14. A reinforcing wire 42 can be positionedbetween the inner tube 38 and the coils 34, 36 to provide for deflectionor steering of the distal end 18. The reinforcing wire 42 can be formedof a material having sufficient strength so that a thin profile ispossible. For example, the reinforcing wire can be an at least partiallyflattened strip of stainless steel that can retain its shape until it isre-shaped to a different configuration. In one configuration, thereinforcing wire 42 is soldered or otherwise connected to the distal endof coil 36 and the remainder of the reinforcing wire 42 extendsproximally to the housing 12. Manipulation of the proximal end of thereinforcing wire 42 allows the user to deflect or steer the distal tip18 without permanently impairing the inner structure of the hollowguidewire 14. The steerable distal tip provides a user with greaterintraluminal control of removing the occlusive or stenotic material fromthe blood vessel and also aids in navigating the hollow guidewire to thetarget site. In another configuration, the reinforcing wire is 42 can besoldered or otherwise connected to both the distal end and to thejunction between coils 34, 36. Therefore, if the coils 34, 36, break,the attached reinforcing wire 42 can prevent the coils 34, 36 fromdetaching from the system 10. A more complete description of the hollowguidewire can be found in commonly owned U.S. patent application Ser.No. 09/030,657, filed Feb. 25, 1998, the complete disclosure of whichwas previously incorporated by reference.

FIGS. 4-9 show various embodiments of the drive shaft 22 of the presentinvention. In most embodiments, the drive shaft 22 is a wire, acounter-wound multiple strand wire, or a plurality of braided wireshaving a body 44 and a shaped distal tip 24. The proximal end of thedrive shaft 22 can be removably coupled to a rotatable motor shaft 48(FIGS. 10 and 11A) or manually manipulated (FIG. 1B). The body 44 of thedrive shaft 22 extends through the elongate member 14 so that the distaltip 24 of the drive shaft is positioned near the distal end of theelongate member 14. The detachable connection to the motor shaft 48allows the drive shaft 22 and elongate member 14 to be detached from themotor shaft 48 and connector assembly 30 so that an access or supportsystem can be placed over the elongate member and advanced through thebody lumen.

As shown in FIGS. 4 and 5A-5C, the distal tip can be shaped or deflectedfrom the longitudinal axis 50 to extend beyond the radius of theelongate member 14 such that rotation of the drive shaft 22 creates apath radius 52 that is as at least as large as the radius 54 of thedistal end of the elongate member 14. In other embodiments, the distaltip 24 will be deflected and shaped so as to create a path radius 52which is the same or smaller than the radius of the distal end of theelongate member 14 (FIGS. 8B-8G). For example, in one exemplaryconfiguration shown in FIG. 5C, a portion of the distal tip 24 extendsbeyond the distal end 18 of the elongate member when in the fullyretracted position. When the drive shaft 22 is advanced out of theelongate member 14, the flexible distal tip 24 maintains a deflectedshape (FIG. 5A). In alternative configurations, it is contemplated thatthe deflection at the distal tip 24 can straighten somewhat under theforce from the walls of the elongate member 14 when the drive shaft 22is retracted into the elongate member 14 (FIG. 5B). Thus, in the axiallyretracted configuration, the drive shaft 22 will have a profile that issmaller than the radius of the distal tip of the elongate member. Whenthe drive shaft is advanced out of the distal end of the elongatemember, the drive shaft will expand to an axially extended configurationin which the distal tip of the drive shaft 22 will have a profile thatis larger than the axially retracted configuration, and in someembodiments will have a larger profile than the distal end of theelongate member 14.

Referring again to FIG. 4, in some configurations a layer of abrasivematerial 56 can be attached and distributed over at least a portion ofthe distal tip 24 of the drive shaft 22 so that the abrasive material 56engages the stenotic or occlusive material as the drive shaft 22 isadvanced into the occlusion or stenosis. The abrasive material 56 can bediamond powder, diamond chips, fused silica, titanium nitride, tungstencarbide, aluminum oxide, boron carbide, or other conventional abrasiveparticles.

Alternatively, as shown in FIGS. 6A-6D, the distal tip 24 of the driveshaft 22 can be sharpened to facilitate passing through the occlusion orstenosis. A distal edge of the tip 24 can be sharpened so as to define acutting edge 58 which rotatably contacts the occlusive or stenoticmaterial. In an exemplary embodiment illustrated in FIGS. 6B-6C, a tip60 of the drive shaft can be sharpened to create a plurality of cuttingedges 58. Furthermore, as shown in FIG. 6D and as described above, thedistal tip 24 can be deflected from its longitudinal axis 50 to createthe cutting path radius 52 of the drive shaft 24 that is smaller,larger, or the same length as the radius of the elongate member 14.

The drive shaft 22 can be composed of a shape retaining material, arigid material, a flexible material, or can be composed of a pluralityof materials. For example in some configurations, the drive shaft 22 canbe comprised of nitinol, stainless steel, platinum-iridium, or the like.The distal tip 24 of the drive shaft 22 can have an enlarged tip, apreformed curve, or a preformed deflection (FIG. 5A). FIGS. 6E and 6Fshow exemplary embodiments of a counter-wound and composite drive shaftsof the present invention. The counter-wound drive shaft 22 shown in FIG.6E is made of a 0.004 inch OD center wire 67 having a right-hand woundsurrounding wire 69 coiled around the center wire 67. The surroundingwire 69 can be soldered to the center wire at both ends of the centerwire. In the embodiment of FIG. 6F, multiple strand wires 51 can bewound around a central coil 71 to form the drive shaft 22. Thecounter-wound drive shafts are significantly more flexible than a singlewire guidewire and allows for a tighter bending radius over conventionalguidewire. FIG. 6G illustrates the flexibility of both a 0.007 inch ODsingle wire stainless steel wire drive shaft 22 a and a 0.007 inch ODcounter-wound stainless steel drive shaft 22 b. As shown by FIG. 6F, thecounter-wound drive shaft has better flexibility, while stillmaintaining its torqueability, maneuverability, and columnar strength.

Additionally, in some embodiments, the distal portion of the drive shaft22 is radiopaque so that a physician can track the position of the driveshaft 22 using fluoroscopy. The drive shaft 24 typically has a diameterbetween approximately 0.010 inches and 0.005 inches. It should beappreciated that the dimension of the drive shaft will be slightly lessthan the inner diameter of the hollow guidewire so as to allow rotationwithout significant heat generation. Consequently, the dimensions of thedrive shaft will vary depending on the relative inner diameter of theelongate member 14 and the present invention is not limited to the abovedescribed dimensions of the drive shaft.

In one embodiment, the distal tip 24 of the drive shaft is created usinga shaped fixture 64. As shown in FIGS. 7A and 7B, the distal tip 24 ispositioned on the fixture 64 and bent to a desired angle 66. The distaltip 24 can be bent to almost any angle 66 between 0° degrees and 90°degrees from the longitudinal axis 50, but is preferably deflectedbetween 0° degrees and 50° degrees. As shown in FIG. 7C, a sharpenededge 58 can be created on the distal tip using a wafer dicing machineused in the production of silicon microchips (not shown). The angle ofthe sharpened edge 58 can be almost any angle, but the angle istypically between 0° degrees and 45° degrees, and is preferably betweenapproximately 8° degrees and 18° degrees. Naturally, it will beappreciated that a variety of methods can be used to manufacture thedistal tip of the drive shaft and that the present invention is notlimited to drive shafts produced by the described method.

As mentioned above, the distal tip 24 can take various shapes. Oneembodiment having a deflected distal tip 24 is shown in FIG. 8A. In anexemplary configuration, the deflected tip is offset at an angle suchthat rotation of the drive wire 22 defines a profile or path that is atleast as large as the outer diameter of the distal end of the elongatemember 14. As shown in FIGS. 8B and 8C, in other embodiments, the tipcan be deflected at other angles and may have a length that creates apath that is smaller or the same diameter as the distal end of theelongate member. The deflected distal tip can extend radially anyfeasible length beyond the perimeter or diameter of the elongate member14. It should be understood that the invention is not limited to asingle deflected tip. For example, the drive shaft can comprise aplurality of deflected tips. Alternatively, the drive shaft may have adistal tip 24 that is twizzle shaped, spring shaped, twisted metalshaped (FIG. 8D), ball shaped (FIG. 8E), a discontinuous surface (FIG.8F), or the like. Alternatively, the drive shaft may comprise aplurality of filaments (FIG. 8G), rigid or flexible brush elements, aplurality of coils, or the like.

The distal tip of the drive shaft can be configured optimally for thetype of occlusion or stenosis to be penetrated. Some lesions are made upsubstantially of clot or thrombotic material that is soft andgelatinous. FIGS. 8H and 8K shows distal tip embodiments which may beused to macerate a soft clot, thrombotic material, or stenosis. FIG. 8Hshows a distal tip 24 having a basket like construction which is made upof a plurality of strands 59 that are connected at their ends 61, 63. Inanother embodiment illustrated in FIG. 8I, the distal tip 24 can becomposed of a plurality of strands 59 that are unconnected at theirdistal ends 63. Additionally, the distal ends 63 of the strands 59 canbe turned inward so that the distal ends 63 do not penetrate the bodylumen when rotated. FIG. 8J shows a corkscrew spiral distal tip having ablunt distal end 63. FIG. 8K shows a distal tip having a loopconfiguration.

In use, the distal tip 24 is rotated and advanced distally from aretracted position to an expanded position into the soft material in thetarget lesion. If slow speed rotation is desired the user can rotate thedrive shaft slowly by hand by grasping a knurled knob attached to theproximal end of the drive shaft (FIG. 1B). If high speed rotation isdesired, the proximal end of the drive shaft 22 can be attached to thedrive motor 26. As the expanded wire basket tip is rotated, the tipmacerates the soft clot and separates the clot from the wall of the bodylumen. If a large diameter hollow guidewire working channel is used todeliver the drive shaft to the target area, the macerated clot can beaspirated through the guidewire working channel. Alternatively oradditionally, a fluid, such as thrombolytic agents, can be deliveredthrough the working channel to dissolve the clot to prevent “distaltrash” and blockage of the vasculature with debris from the maceratedclot.

In another exemplary embodiment shown in FIG. 8L, the distal tip 24 ofthe drive shaft 22 can be flattened and twisted to create a screw lietip that can create a path through the occlusion. The flattened andtwisted distal tip 24 can have a same width, a smaller width or a largerwidth than the drive shaft 24. For example, in one configuration for adrive shaft having an outer diameter of 0.007 inches, the distal tip 24can be flattened to have a width between approximately 0.015 inches and0.016 inches, or more. It should be appreciated, however, that thedistal tip can be manufactured to a variety of sizes.

FIGS. 8M-8P show one method of manufacturing the flattened and distaltip of the present invention. The round drive shaft 22 (FIG. 8M) istaken and the distal end is flattened (FIG. 8N). The distal end can besharpened (FIG. 80) and twisted two or two and a half turns (FIG. 8P).If a different amount of twists are desired, the distal tip can bemanufactured to create more (or less) turns.

As shown in FIGS. 9 and 15 in some embodiments the drive shaft 22 canoptionally have spiral threads or external riflings 64 which extendalong the body 44. As the drive shaft 22 is rotated and axially advancedinto the atheromatous material, the distal tip 24 creates a path andremoves the atheromatous material from the blood vessel. The rotatingspirals 64 act similar to an “Archimedes Screw” and transport theremoved material proximally up the axial lumen of the elongate member 14and prevent the loose atheromatous material from blocking the axiallumen of the elongate member 14 or from escaping into the blood stream.

In use, drive shaft 24 is rotated and advanced to create a path distalof the elongate member 14 to create a path through the occlusion. Thedrive shaft 24 can be advanced and rotated simultaneously, rotated firstand then advanced, or advanced first and then rotated. The drive shaft22 is typically ramped up from a static position (i.e. 0 rpm) to about5,000 rpm, 20,000 rpm with a motor. It should be noted, however, thatthe speed of rotation can be varied (higher or lower) depending on thecapacity of the motor, the dimensions of the drive shaft and theelongate member, the type of occlusion to be bypassed, and the like. Forexample, if desired, the drive shaft can be manually rotated orreciprocated at a lower speed to macerate soft clots or to pass throughlesions.

The distal tip of the drive shaft 22 can extend almost any length beyondthe distal portion of the hollow guidewire. In most embodiments,however, the distal tip typically extends about 5 centimeters, morepreferably from 0.05 centimeters to 5 centimeters, and most preferablybetween 0.05 centimeter and 2 centimeters beyond the distal portion ofthe hollow guidewire.

Referring now to FIGS. 10, 11A, and 11B, the motor shaft 48 and theproximal end 46 of the drive shaft 22 are coupled together with adetachable linkage assembly 70. In one embodiment shown in FIG. 10,linkage assembly 70 has a first flange 72 attached to the motor shaft48. The first flange can be snap fit, snug fit, or permanently attachedto the drive shaft 48. A second flange 74 can be permanently orremovably coupled to the proximal end 46 of the drive shaft 22 so thatthe first flange 72 of the motor shaft 48 can threadedly engage thesecond flange 74. In some embodiments, the proximal end of the driveshaft 46 can be enlarged so as to improve the engagement with the secondflange 74. An o-ring 76 is preferably disposed within a cavity in thefirst flange 72 to hold the first flange 72 and second flange 74 infixed position relative to each other.

As shown generally in FIGS. 1 and 11B, the motor 26 can be removablycoupled to the housing 12. To detach the motor 26 and power supply 28from the drive shaft 22, the user can unlock the luer assembly 30 so asto release the elongate member 14 from the housing 12. The drive shaft22 and elongate member 14 are then both free to move axially. The motor26 can be moved proximally out of the housing 12 and the proximal end 46of the drive shaft 22 can be detached from the motor shaft 48. After themotor 26, housing 12, and luer assembly 30 have been uncoupled from theelongate member 14 and drive shaft 22, a support or access system (notshown) can be advanced over the free proximal end of the elongate member14. Thereafter, the luer assembly and motor shaft 48 can be recoupled tothe elongate member 14.

In the embodiment shown in FIGS. 11A and 11B, the linkage assembly 70includes a connecting shaft 78 that can be snugly fit over the motorshaft 48. The connecting shaft 78 preferably tapers from a diameterslightly larger than the motor shaft 48 to a diameter of that of theapproximately the proximal end 46 of the drive shaft 22. In theembodiment shown, the connecting shaft 78 is coupled to the drive shaftthrough shrinkable tubing 80. Because the connecting shaft 78 is snugfit over the motor shaft, (and is not threadedly attached to the driveshaft) the size of the connecting shaft 78 can be smaller than thelinkage assembly 70. While the exemplary embodiments of the connectionassembly between the drive shaft and motor shaft have been described, itwill be appreciated that drive shaft and motor shaft can be attachedthrough any other conventional means. For example, the motor shaft 48can be coupled to the drive shaft 22 through adhesive, welding, a snapfit assembly, or the like.

As shown in FIG. 11B, the drive shaft 22 extends proximally through thehousing 12 and is coupled to the motor shaft 48. An actuator 82 can beactivated to advance and retract the drive shaft 22. In someembodiments, the motor is press fit into the actuator housing 12. Thedrive shaft 22 is attached to the motor shaft 26 via o-rings such thatthe drive shaft 22 can be moved axially through axial movement of theactuator 82.

In most embodiments, actuation of the drive motor 26 and power supply 28(e.g. rotation of the drive shaft) will be controlled independent fromadvancement of the drive shaft 22. However, while the actuator 82 isshown separate from the control system 27 and power supply 28 (FIG. 1),it will be appreciated that actuator 82 and control system 27 can bepart of a single, consolidated console attached to the housing 12 orseparate from the housing 12. For example, it is contemplated that thatthe drive shaft 22 can be rotated and advanced simultaneously byactivation of a single actuator (not shown).

A connection assembly 30 is positioned on a proximal end of the housingto couple the hollow guidewire 14 and the drive shaft 22 to the housing12. In a preferred embodiment shown in FIGS. 12-14, the connectionassembly 30 is a detachable luer which allows the drive shaft 22 to bemoved (e.g. rotated, reciprocated, translated) while the elongate memberis maintained in a substantially static position. FIG. 12 bestillustrates an exemplary luer connection assembly 30 which couples theelongate member 14 and the housing 12. The luer has a gland 86 which isrotatably connected to a fitting 88 and a tubular portion 90. Rotationof the gland 86 rotates and torques the elongate member 14 while theelongate member 14 is advanced through the blood vessel. Fitting 88 isthreaded into the gland 86 such that a distal end of the fitting engagesan o-ring 92 and a surface wall 94 of the gland. The longitudinal axis96 of the fitting 88 and gland 86 are aligned so as to be able toreceive the axial lumen of the elongate member 14. As the fitting 88engages the o-ring 92, the o-ring is compressed radially inward tosqueeze and maintain the position of the elongate member 14.Accordingly, as illustrated in FIG. 13, when the drive shaft 22 isrotated within the elongate member 14, the o-ring 92 is able tosubstantially maintain the position and orientation of the elongatemember 14. Tubular portion 90 attached to the proximal end of thefitting 88 threadedly engages the housing 12 and enables the luerconnection assembly 30 to be removed from the housing 12 (FIG. 14). Amore complete description of the connection assembly 30 can be found incommonly owned U.S. patent application Ser. No. 09/030,657, filed Feb.25, 1998, the complete disclosure of which was previously incorporatedby reference. It should be appreciated that the present invention is notlimited to the specific luer assembly described. Any luer assembly canbe used to connect the elongate member 14 to the housing 12. Forexample, a Y-luer assembly (not shown) can be used with the system ofthe present invention to infuse or aspirate of fluids through the lumenof the hollow guidewire 14.

As shown in FIGS. 3 and 15, systems of the present invention can furtherinclude an access or support system 98. The access or support system 98can be an intravascular catheter such as a hollow guidewire supportdevice, support catheter, balloon dilation catheter, atherectomycatheters, rotational catheters, extractional catheters, conventionalguiding catheters, an ultrasound catheter, a stenting catheter, or thelike. In an exemplary configuration shown in FIG. 15, the systemincludes an infusion or aspiration catheter which has at least one axialchannel 100, and preferably a plurality of axial channels 100 whichextends through the catheter lumen 102 to the distal end of thecatheter. The elongate member 14 and drive shaft 22 can be positionedand advanced through the lumen 102 of the catheter. The axial channel 20of the elongate member 14 and/or the axial channels 100 of the catheter98 can also be used to aspirate the target site or infuse therapeutic,diagnostic material, rinsing materials, dyes, or the like.

The access or support system can be guided by the elongate member to thetarget site in a variety of ways. For example, as illustrated in FIGS.16A to 16E, a conventional guidewire 104 can be advanced through theblood vessel BV from the access site (FIG. 16A). Once the guidewire 104has reached the target site, the support or access system 98 can beadvanced over the guidewire 104 (FIG. 16B). Alternatively, the guidewire104 and support or access system 98 can be simultaneously advancedthrough the body lumen (not shown). Once the support or access system 98has reached the target site, the conventional guidewire 104 can beremoved and the hollow guidewire 14 having the drive shaft 22 can beintroduced through the lumen 102 of the access system 98 (FIG. 16C).Even if the distal tip 24 of the drive shaft 22 is not fully retractedinto the axial lumen 20, the lumen 102 of the support or access systemprotects the blood vessel BV from damage from the exposed distal tip 22.In most methods, the support or access system is positioned orstabilized with balloons, wires, or other stabilization devices 106 toprovide a more controlled removal of the occlusive or stenotic materialOM. Once the drive shaft 22 has reached the target site, the drive shaftcan be rotated and advanced into the occlusive or stenotic material OMto create a path (FIGS. 16D and 16E).

In another method of the present invention, the hollow guidewire 14 canbe used to guide the support or access system to the target site withoutthe use of a separate guide wire. The hollow guidewire 14 provides theflexibility, maneuverability, torqueability (usually 1:1), and columnarstrength necessary for accurately advancing through the tortuousvasculature and positioning the distal end of the support or accesssystem at the target site. The steerable distal portion can be deflectedand steered through the tortuous regions of the vasculature to get tothe target site. As shown in FIG. 17A, the hollow guidewire is advancedthrough the tortuous blood vessel to the target site. Due to the smallsize of the guidewire 14 relative to the blood vessel, even if thedistal tip 24 of the drive shaft 22 extends partially out of the hollowguidewire 14, any potential damage to the blood vessel BV will beminimal.

Once the hollow guidewire reaches the target site within the bloodvessel, the motor shaft 48, luer assembly 30, and housing 12 can bedetached from the proximal end 46 of the drive shaft 22 so that thesupport or access system can be placed over the hollow guidewire. Afterthe motor has been detached, the support or access system can beadvanced over the guidewire and through the body lumen to the targetsite (FIG. 17B). To reattach the drive motor 26 to the drive shaft 22,the hollow guidewire 14 and drive shaft 22 are inserted through the luerassembly 30. The luer assembly 30 is tightened to lock the position ofthe hollow guidewire 14. The drive shaft 22 will extend proximallythrough the housing 12 where it can be recoupled to the motor shaftusing the above described linkage assemblies 70 or other conventionallinkage assemblies. Once at the target site, the position of the supportor access system 98 can be stabilized by a balloon, wires, or otherstabilizing devices 106, and the drive shaft 22 can be rotated andadvanced into the occlusive or stenotic material OM (FIGS. 17C and 17D).The rotation of the drive shaft creates a path forward of the distal end18 of the hollow guidewire 14. As noted above, the path can have thesame diameter, smaller diameter, or larger diameter than the distal endof the hollow guidewire. Before, during, or after the rotation of thedrive shaft, the user can steer or deflect the distal end 18 of thehollow guidewire 14 to guide the hollow guidewire to the desiredlocation within the blood vessel. For example, as shown in FIG. 17E,once a portion of the occlusion or stenosis has been removed, the distalend 18 of the hollow guidewire 14 can be guided to angle the distal endso that the drive shaft is extended into a different portion of theocclusive or stenotic material OM.

While the apparatus of the present invention is sufficient to create apath through the occlusion OM without the use of a support or accesssystem, the apparatus 10 of the present invention can be used inconjunction with other atherectomy devices to facilitate improvedremoval or enlargement of the path through the occlusion. For example asshown in the above figures, the hollow guidewire 14 and the atherectomydevice 108 can be advanced through the body lumen and positionedadjacent the occlusion OM. The drive shaft 22 is rotated and advanced tomake an initial path through the occlusion (FIG. 18A). The hollowguidewire 14 is then moved through the path in the occlusion and theatherectomy device 108 can then be advanced over the hollow guidewire 14into the path in the occlusion OM to remove the remaining occlusion withcutting blades 110, or the like (FIG. 18B). While FIG. 18B shows cuttingblades 110 to remove the occlusive material OM, it will be appreciatedthat other removal devices and techniques can be used. Some examplesinclude balloon dilation catheters, other atherectomy catheters,rotational catheters, extractional catheters, laser ablation catheters,stenting catheters, and the like.

In another aspect, the invention provides medical kits. As shown in FIG.19, the medical kit generally includes a system 10, instructions for use(IFU) 120 which describe any of the above described methods, and apackage 130. The IFU can be separate from the package or they can beprinted on the package. The kits can also optionally include anycombination of a second guidewire, a motor, a power supply, a plasticsheath cover, connection assemblies, support or access systems, or thelike.

While the above is a complete description of the preferred embodimentsof the invention, various alternatives, modifications, and equivalentsmay be used. Therefore, the above description should not be taken aslimiting the scope of the invention which is defined by the appendedclaims.

1. A method for crossing an occlusion in a blood vessel, the methodcomprising: advancing an elongate member through a blood vessel to alocation proximate an occlusion, the elongate member having a proximalend removably coupled to a housing and a drive shaft rotatably disposedwithin the elongate member extending from a motor positioned in thehousing to a distal tip rotatably disposed at a distal end of theelongate member; rotating the drive shaft within the elongate memberwith the motor to form or enlarge a pathway through the occlusion withthe distal tip; decoupling the housing from the elongate member whileretaining the elongate member in the blood vessel proximate theocclusion; and advancing an access device over the elongate member tothe occlusion after decoupling the housing from the elongate member. 2.The method of claim 1, wherein the elongate member serves as a guidewireto guide the access device to the occlusion without the use of aseparate guidewire.
 3. The method of claim 1, wherein decoupling thehousing from the elongate member includes unlocking a luer assembly soas to release the elongate member from the housing.
 4. The method ofclaim 1, further comprising: detaching the motor from the drive shaft.5. The method of claim 1, wherein the motor and drive shaft are coupledtogether with a detachable linkage assembly.
 6. The method of claim 1,wherein the elongate member has an outer diameter of betweenapproximately 0.009 inches and approximately 0.040 inches.
 7. The methodof claim 1, wherein the distal tip creates a path radius at least aslarge as a radius of the distal end of the elongate member.
 8. Themethod of claim 1, wherein the elongate member includes a coil proximatethe distal end of the elongate member.
 9. The method of claim 1, whereinthe access device is an intravascular catheter.
 10. A method forcrossing an occlusion in a blood vessel, the method comprising:advancing a hollow guidewire through a blood vessel to a locationproximate an occlusion, the guidewire having a proximal end removablycoupled to a housing and a drive shaft extending through the hollowguidewire, a proximal end of the drive shaft being coupled to a motorshaft of a motor positioned in the housing and a distal end of the driveshaft being coupled to a distal tip rotatably disposed at a distal endof the guidewire; rotating the drive shaft within the guidewire with themotor to form or enlarge a pathway through the occlusion with the distaltip; decoupling the guidewire and the drive shaft from the housing andthe motor shaft, respectively, while retaining the guidewire in theblood vessel proximate the occlusion; and advancing an intravascularcatheter over the guidewire to the occlusion after decoupling theguidewire and the drive shaft from the housing and the motor shaft. 11.The method of claim 10, wherein the guidewire serves to guide theintravascular catheter to the occlusion without the use of a separateguidewire.
 12. The method of claim 10, wherein the guidewire has anouter diameter of between approximately 0.009 inches and approximately0.040 inches.
 13. The method of claim 10, wherein decoupling the housingfrom the guidewire includes unlocking a luer assembly so as to releasethe guidewire from the housing.
 14. The method of claim 10, wherein themotor shaft and drive shaft are coupled together with a detachablelinkage assembly.
 15. The method of claim 10, wherein the distal tipcreates a path radius at least as large as a radius of the distal end ofthe guidewire.
 16. The method of claim 10, wherein the guidewireincludes a coil proximate the distal end of the guidewire.
 17. Themethod of claim 10, wherein the intravascular catheter is a ballooncatheter.